The present disclosure relates to memory devices and a methods of forming the same, and more particularly, to magnetic memory devices and methods of forming the same.
As high speed and low power consumption electronic devices are realized, memory devices built in the electronic devices also require rapid read/write performance and low operation voltages. Magnetic memory devices are being studied as memory devices that may satisfy these requirements. Because magnetic memory devices have generally high-speed performance and/or non-volatile characteristics, they have drawn attention as a next generation memory.
Commonly known magnetic memory devices may include a magnetic tunnel junction (MTJ). The magnetic tunnel junction is formed by two magnetic substances and an insulation layer interposed therebetween, and the resistance of the magnetic tunnel junction may vary with the magnetization directions of the two magnetic substances. Specifically, when the magnetization directions of the two magnetic substances are anti-parallel to each other, the magnetic tunnel junction may have a relatively high resistance. When the magnetization directions of the two magnetic substances are parallel to each other, the magnetic tunnel junction may have a relatively low resistance. The difference between these resistances may be used to write/read data.
Tunneling magneto resistance (TMR) is calculated from the ratio of the difference between resistances in the anti-parallel state and parallel state to the resistance in the parallel state. Therefore, as the resistance ratio increases, TMR increases.